Zinc isotopes from archaeological bones provide reliable trophic level information for marine mammals

• Published in: Communications Biology
• Main Authors: Mccormack, Jeremy, Szpak, Paul, Bourgon, Nicolas, Richards, Michael, Hyland, Corrie, Méjean, Pauline, Hublin, Jean-Jacques, Jaouen, Klervia
• Other Authors: Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: envir; geo; Arctic; Pusa hispida; Ursus maritimus
• Online Access: https://doi.org/10.1038/s42003-021-02343-3; https://hal.archives-ouvertes.fr/hal-03518913/file/McCormacketal2021.pdf; https://hal.archives-ouvertes.fr/hal-03518913

International audience In marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate the geographic variability and trophic level isotopic discrimination factors of bone zinc 66 Zn/ 64 Zn ratios (δ 66 Zn value) and compared it to collagen nitrogen and carbon stable isotope (δ 15 N and δ 13 C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ 66 Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ 15 N and δ 66 Zn values in all locations, yet δ 66 Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ 15 N and δ 13 C analysis alone. When combining all three proxies, a more detailed and refined dietary analysis is possible.